Learning To Help: Training Models to Assist Legacy Devices
Yu Wu, Anand Sarwate
TL;DR
This work addresses extending ML inference to legacy devices by offloading to edge servers through a Learning to Help framework, where a fixed local classifier $m(x)$ is assisted by a learnable edge classifier $e(x)$ and a rejection rule $r(x)$. By formulating a generalized 0-1 loss with abstention cost $c_e$ and edge error cost $c_1$, the authors derive Bayes-optimal rules, establish a generalization bound via Radamacher complexity, and introduce a convex, differentiable surrogate loss $L_S$ with calibration guarantees to train the edge and rejector. Empirical results on CIFAR-10 binary tasks show that Learning to Help outperforms confidence-based rejection methods and benefits from joint training of $r$ and $e$ while keeping $m$ fixed. The framework offers a practical pathway to prolong legacy hardware functionality in MEC settings and motivates future work on multi-server extensions and broader deployment scenarios.
Abstract
Machine learning models implemented in hardware on physical devices may be deployed for a long time. The computational abilities of the device may be limited and become outdated with respect to newer improvements. Because of the size of ML models, offloading some computation (e.g. to an edge cloud) can help such legacy devices. We cast this problem in the framework of learning with abstention (LWA) in which the expert (edge) must be trained to assist the client (device). Prior work on LWA trains the client assuming the edge is either an oracle or a human expert. In this work, we formalize the reverse problem of training the expert for a fixed (legacy) client. As in LWA, the client uses a rejection rule to decide when to offload inference to the expert (at a cost). We find the Bayes-optimal rule, prove a generalization bound, and find a consistent surrogate loss function. Empirical results show that our framework outperforms confidence-based rejection rules.
